Macro inputln

macro_rules! inputln {
    () => { ... };
    ($($arg:tt)*) => { ... };
}

A macro that:

• prints the prompt on its own line (with println!),
• then reads one line,
• returns Ok(None) on EOF,
• otherwise parses into String.

Usage:

let line: Option<String> = inputln!("What's your favorite color?").unwrap();